Today, an anonymous group hacked the BigBoss repo. According to iDownloadBlog, the unknown hackers gained access to all packages in the repo, and made a separate repo that makes all of the packages free. Do not add this repo because not only is it piracy, it also may contain malicious software. And to be safe, i advise you to not install or upgrade any packages in the BigBoss repo until this is under control.

Update: It is safe to install/update packages from BigBoss. Saurik has released this statement:

"[iDownloadBlog] mentions malware being potentially injected into the BigBoss repository; we do not believe this to be the case. Packages in Cydia repositories are cryptographically verified from the repository package index. I have an index of all historic changes to the package indices for default repositories, and have verified that the content on BigBoss did not change in ways that the repository administrators did not expect."